To indicate a student has not turned in an assignment, use the last three Special Marks defined on the screen. A score of 0 may also be considered missing, but only if you check "0 also means Missing" on the screen and your grade scale uses percents.
To list missing assignments for each student, print or send and check the option "List of missing assignments only".
When you are done grading an , click the "Fill" button to mark any remaining blanks as missing (this is a shortcut for the "Fill blanks" menu). (It uses the first Special Mark you define as Missing, or 0 if it's not defined.)
Note: Blanks are not considered "missing". A blank score simply means the assignment has not been graded yet. That way you can list upcoming homework without hurting students' grades.
Missing assignments appear on the student's Homework screen. For example, if they miss an assignment last week (and you mark it missing), they'll see it included with their homework tonight. If they still don't complete it, it will remain on the homework list tomorrow night, and so on. It shows only the last missing assignment in each class, so the student is has an achievable goal and isn't overwhelmed with a long list. They can always look on the Details screen for that.
Parents can receive automated alerts whenever any assignment is missing. They will continue to receive alerts every week or every day as long as the assignment is still marked missing. For this reason, if it is too late to turn in an assignment, you should change the score to a 0, F, or other special mark so it is no longer marked as missing.